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  <meta charset="UTF-8">
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  <title>Document</title>
</head>
<body>
  <script>
    //声明map
    let m = new Map()

    m.set('name', 'shangguigu')
    m.set('change', function(){
      console.log('change world')
    })
    let key = {
      name: 'atguihu',
    }
    m.set(key,['shanghai','beijing'])
    console.log(m)

    console.log(m.size)
    m.delete('name')

    console.log(m.get(key))
    m.clear()
    console.log(m)
  </script>
</body>
</html>